Humping is usually a show of dominance and doesn't have anything to do with sexual behavior. Many dogs will do it when over stimulated and stressed and it serves as a kind of release for pent up energy or anxiety. Most dogs will do it with other dogs, but if an animate object is unavailable - the blanket will do!

My first question is whether or not the dog is neutered. Studies show that neutered dogs are less likely to exhibit the behavior.

My second question is what kind of background does this dog have. You say it was your Aunt's dog and now it is yours. Is this a recent thing. My gut feeling is that Rico is a little stressed and could be acting up.

I would suggest the following:

1. Training classes. Training classes will help Rico see you as the caregiver and leader of the pack. It will also help him become more confident and less stressed.

2. Nothing in Life is Free - if he knows sit and down, make him do a sit or a sit/down for everything. Make him "sit" before you give him his dinner. Make him "sit" before you put a leash on him or let him go outside. Make him "down" before getting treats or a toy. If he doesn't know sit or down yet - teach it to him.

3. Mounting behavior - redirect. Say "no" and then redirect his energy with something else. A game of fetch, or a short training session - then praise the good behavior.

My gut feeling is that this could be a result of anxiety. I think once he feels more comfortable and starts gaining in confidence you could see a turn around in this behavior.

Good Luck and welcome to Pet talk!